Hong Kong Med J 2002;8:427-34 | Number 6, December 2002
Use of the low-dose corticotropin stimulation test for the diagnosis of secondary adrenocortical insufficiency
CH Choi, SC Tiu, CC Shek, KL Choi, FKW Chan, PS Kong
Department of Medicine, Queen Elizabeth Hospital
OBJECTIVE. To assess the clinical utility and safety of the low-dose corticotropin stimulation test in the diagnosis of secondary adrenocortical insufficiency.
DESIGN. Prospective study.
SETTING. Regional hospital, Hong Kong.
PARTICIPANTS. Seventy-two Chinese patients with suspected secondary adrenocortical insufficiency.
MAIN OUTCOME MEASURE. Serum cortisol response during the low-dose corticotropin stimulation test, using the insulin tolerance test as the gold standard.
RESULTS. The 30-minute cortisol level during the low-dose corticotropin stimulation test was most closely correlated (r=0.79) with the peak cortisol level achieved during the insulin tolerance test. The optimum sensitivity and specificity of the low-dose corticotropin stimulation test were obtained at a cut-off value of 550 nmol/L or more for the 30-minute cortisol level. Using the insulin tolerance test as the gold standard for comparison, the low-dose corticotropin stimulation test had a sensitivity of 97%, a specificity of 78%, a positive predictive value of 81%, and a negative predictive value of 97% at this cut-off value. The positive likelihood ratio was 4.4 and the negative likelihood ratio 0.04.
CONCLUSION. The low-dose corticotropin stimulation test, using the cortisol response at 30 minutes after synacthen 1 µg is a safe, convenient, and sensitive method for screening abnormalities of the hypothalamic-pituitary-adrenocortical axis in Chinese patients suspected of having secondary adrenocortical insufficiency.
Key words: Adrenal gland hypofunction; Corticotropin; Diagnosis
View this abstract indexed in MEDLINE: